The present invention relates to cervical carcinoma cells (HeLa) modified with a nitrate reductase gene fragment.
U.S. Pat. No. 5,003,050, "Diazoluminomelanin and a method for preparing same", issued Mar. 26, 1991 to Kiel et al, describes a polymeric water-soluble luminescent compound having repeating units comprising diazo-linked luminol and hydroxyindole and referred to as diazoluminomelanin (DALM). DALM can be used for chemiluminescent immunoassays for biological and chemical agents; in radiofrequency and ionizing radiation dosimeters; and for RNA/DNA hybridization assays for viruses and genetic detection.
It was found that DALM can be biosynthesized by culturing a microorganism containing nitrate reductase in a medium containing nitrate, 3-aminog-L-tyrosine (3-AT) and luminol under suitable metabolic conditions. U.S. Pat. No. 5,856,108,"Biosynthesis of diazomelanin and diazoluminomelanin and methods thereof", issued Jan. 5, 1999 to Kiel et al.
U.S. Pat. No. 5,464,768,"Enhanced nitrite production in transfected murine cells", issued Nov. 7, 1995 to Kiel et al, describes mammalian cells line capable of enhanced nitrite production prepared by transfecting a murine macrophage or murine thymoma with barley nitrate reductase gene (NR). The cell lines can be used for the production of diazomelanin (DM) and diazoluminomelanin (DALM). Production of DM is achieved by culturing the cells in a medium containing a nitrate source and 3-amino-L-tyrosine under suitable metabolic conditions.
We then successfully modified EMT-6 cells (spontaneous Balb/c mammary adenocarcinoma cell line) with the chromosomal insertion of the plasmid pSV.sub.2 neoNR10.sub.1, ATCC No. 69617. U.S. Pat. No. 6,013,520, "Breast tumor cells for study of nonionizing radiation effects", issued Jan. 11, 2000 to Parker et al. The transformed cells, EMT-6/pSV.sub.2 neoNR10.sub.1, produce diazoluminomelanin (DALM) intra cellularly when provided with nitrate, luminol and 3-amino-L-tyrosine.cndot.HCI (3AT). The modified cells can be used to study mechanisms for radiofrequency and light radiation interactions with breast tumor cells in vitro and in mice. The effects of drugs, hormones, and cytokines that affect the expression of nitric oxide synthase and its activity can also be studied to understand the effects of these materials on breast tumor cells.
Cervical cancer is one of the most common malignancies in women and remains a significant public health problem throughout the world. In the United States alone, invasive cervical cancer accounts for approximately 19% of all gynecological cancers. In 1996, it is estimated that there will be 14,700 newly diagnosed cases and 4900 deaths attributed to this disease. In many developing countries, where mass screening programs are not widely available, the clinical problem is more serious. Worldwide, the number of new cases is estimated to be 471,000 with a 4 year survival rate of 40%.
Previous attempts to transfect human cells with a functional nitrate reductase gene have not, until now, been successful. We have now transfected a human cell line, HeLa, with a barley nitrate reductase gene fragment. This cell line can be traced back to a woman named Henrietta Lacks, who died of cervical cancer in the early 1950s.
Accordingly, it is an object of the present invention to provide a human carcinoma cell modified with a nitrate reductase gene fragment.
Other objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.